Disclosed is a device and method for optical supervisory channel framing in an optical transport network system including at least one of an optical transmission section, an optical multiplex section, and an optical channel section. A maintenance signal is generated according to a first LOS (Loss OF Signal) signal generated from at least one of the optical transmission section, the optical multiplex section, and the optical channel section. The maintenance signal and a frame-related channel such as a message communication channel are multiplexed to generate an optical supervisory channel frame. The optical supervisory channel frame is output to another device including a repeater and a terminal system through a single supervisory channel.